1. Field of the Method and Apparatus
The present invention generally relates to apparatuses and methods for installing structural, non structural, circumferential and non circumferential membranes to the interior surfaces of conduits and passageways and more specifically speaks about the ability to ensure the exact membrane thickness on all pre existing undulations or irregularities in the substrate of the conduit and passageways.
2. Description of Related Art
Prior art demonstrates numerous methods to rehabilitate pipelines, conduits and passageways from the inside in order to restore asset integrity. With general infrastructure within the US and around the world in a precarious state of decay, it has been the object of many to provide for a cost effective method to perform in situ-rehabilitation of these properties. In the global municipal arena, waste collection and water distribution systems are seriously compromised with failures creating community disturbances, commercial loss and environmental incidents. In the industrial sector, process lines and transmission lines carry volatile and dangerous materials. These lines are constantly at risk of failure due to age, neglect or lack of funds to replace or repair with traditional methods. The US EPA Clean Water Act of 1989 outlines mandatory restrictions and covenants imposed on municipalities to improve the conditions of their water and wastewater systems. The EPA Conference of Mayors report of 2007 surveys 1500 US Cities' infrastructure needs resulting in $15B in needed repairs and upgrades. The RSCA has also increased scrutiny on chemical processing facilities and pipeline transmission calling for proactive inspection and repair of millions of miles of pipe, conduit and passageway.
In situ repair methods incorporating a resin impregnated lining tube as described by Wood et al, U.S. Pat. No. 5,409,561 and Kliest, U.S. Pat. No. 6,427,726 have demonstrated a good level of success in limited environments. In these cured-in-place (CIPP) materials, e.g., polyester, vinyl ester and even epoxy resin matrices, are combined with a tubular textile material, positioned within the deteriorated line section, forced into intimate contact with the interior surface of the pipe and allowed to cure. While these methods and associated apparatuses have proven viable, there are many instances and conditions where they are either not practical or unsuitable for difficult applications. Processing times are hours to days, restoration of service laterals is required and aggressive environments sometimes preclude their use. Labor and material costs are significant with CIPP processes but still considerably less than traditional construction methods. In order to address these short comings, others have attempted to design alternate systems incorporating automated application and high performance lining materials.
One of the common chemicals used in lining compositions is styrene. Styrene has a negative environmental footprint and is a suspected carcinogen. Other compositions include plasticizers and catalysts. These chemical continue to be released into pipe flow for years after the installation. Further it is a thermosetting resin. This resin shrinks causing an annulus which in turn lets infiltration back into the pipeline flow. Some pipe lining methods use hot water as an activating agent. This method requires large quantities of the heated water to be placed immediately proximate to the pipeline access. Creating this access often requires the removal of trees or disruption of vegetation.